It may seem strange to classify the pro- by sdfsb346f

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									     Plug into data                                Despite 10 years of stop/go,
                                                                                                     gle standard, but this is proving chal-
                                                                                                     lenging. Last year, the IEEE defined a
                                                   broadband over powerlines                         new project in its P1901 effort, with ini-
                                                                                                     tial emphasis on specifications on the
                                                   could be an ‘emerging market’.                    PHY and MAC layers.
                                                                                                         BPL to homes and offices is attracting
                                                   By John Walko.                                    attention because it can transform sockets
                                                                                                     into internet portals, says Jim Mollenkopf,
                                                                                                     cochair of the IEEE’s BPL PHY/MAC
                                                   dynamic host configuration protocol               Working Group. “If BPL is to become
                                                   router is positioned on a pole next to a          widespread, there is a need for a robust
                                                   transformer, serving five to eight homes          standard that supports the use of many
                                                   with a shared medium service. No IP               types of BPL device. Our intent is for
                                                   addressable node is necessary between             P1901 to be that standard.”
                                                   this unit and a platform in the home with             Meanwhile, ETSI is
                                                   an IP address, such as a computer or a            defining a coexistence
                                                   WiFi router. Consequently, the most               layer for BPL that


     I
         t may seem strange to classify the pro-   popular architecture for embedding                many consider is
         vision of broadband over powerlines as    MAC and PHY in first generation sys-
         an emerging market: the idea is hardly    tems is an Ethernet adapter in a wall
     new and has been a ‘dark horse’ data access   socket that provides pass through service
     option for more than a decade.                to a pc or router.
         But recent progress in standardisa-           Commercially, Google caused a buzz
     tion, regulation and technology are           last year when it joined with other compa-
     prompting some observers to believe the       nies to invest a reported $100million in –
     approach – maybe even the economics –         and back a project with – US utility Cur-
     is finally coming right.                      rent Communications. Meanwhile, IBM
         Others contend the power grid will        signed a deal with a Texas based power
     never be a viable, safe, and cost effective   provider CenterPoint Energy to test BPL
     way of delivering internet access, forget-    based last mile access technologies.
     ting there are numerous trials and some           Several European utilities – notably in
     small commercial deployments in               Spain, Portugal and France – have trials or
     Europe and the US.                            small scale commercial offerings. How-
         The idea is also getting a boost from     ever, this should be offset against some
     the separate, but related, efforts of sup-    expensive failures. For instance, a major
     pliers and trade groups – not least the       trial operating between 1997 and 1999 in
     HomePlug Power Alliance (HPA) – to            the Manchester area involving Nortel Net-
     establish networking in the home by           works and Norweb/United Utilities had to
     plugging into the mains, rather than          be abandoned due to technical – mainly
     using coax cables or wireless routers.        interference – and economic reasons.
                                                                                                   Illustration: Elly Walton




         Architecturally, broadband over pow-          Meanwhile, groups such as the IEEE
     erlines (BPL) is a shared medium distri-      and the European Telecommunications
     bution system, but with some specific         Standards Institute (ETSI) are working
     requirements. The equivalent of a             behind the scenes to come up with a sin-




18                                                                         N e w E l e c t r o n i c s w w w. n e o n . c o . u k 9 M a y 2 0 0 6
                  EMERGING MARKET                                                            SPECIAL REPORT


crucial to a future                                                        fact that the US       vendors implied DS2’s chips do not
standard.                                                                  calls the technology   deploy in silicon the kind of notch filters
    The HPA has                                                            BPL, whilst Euro-      needed to minimise interference with
already      defined                                                       peans prefer Power     amateur radio and emergency radio
PHY and MAC                                                                Line Communica-        bands; the problem being potentially
chips for the                                                              tions (PLC).           most serious with medium voltage
200Mbit/s exten-                                                               Europe, backed     topologies from the home. Such notches
sion to the in build-                                                      by the Universal       are designed to keep BPL signals out of
ing      networking                                                        Powerline Associa-     bands that could cause interference.
standard Home-                                                             tion (UPA), is             HPA members emphasise their work
Plug AV. Chip sam-                                                         firmly behind the      with OFDM modulation and notch filter-
ples that support HomePlug AV are just             specification proposed by OPERA – the          ing. Philip Poulidis, senior director of BPL
beginning to appear.                               Open PLC European Research Alliance.           standards at Intellon, said his company’s
    The AV specifications – based on               The group maintains this is the first and      chip set implements a number of notch fil-
technology from companies such as                  only ‘open’ PLC acess specification.           ters in silicon and works with system part-
Intellon, Conexant, Sharp and systems                  The technology, based on previous          ners to use soft, programmable filters for
specialist Arkados – have taken some               chip design by Spain’s Design of Systems       specific geographical problems.
three years to develop.                            in Silicon (DS2), has been developed               Jorge Blasco, DS2’s ceo (pictured oppo-
    Crucially, HPA has recommended the             over the past three years by 37 members,       site), suggests using the same PHY and
same PHY and MAC for the BPL solu-                 comprising industrial groups, universi-        MAC for access and home networking
tion, a decision that could see unwelcome          ties and power utilities. The project, val-    makes no sense from either the network
delays and a potential standards war.              ued at €20m, is part funded by the EC.         topology or performance view-
                       There are several               The specification, again at                point. “One competitor
                     fronts opening up –           200Mbit/s, defines a PHY and MAC for           claims to have solved
                          typified by the          BPL access and a complementary system          the issue, but the
                                                   specification. The group stresses the          reality is they have
                                                   specification allows for interoperability      fixed notches that
                                                   for non OPERA technologies through a           will be difficult, if
                                                   mechanism that guarantees backwards            not impossible, to
                                                   compatibility with today’s deployments.        upgrade to new
                                                       Even though both proposals are based       radio        services.”
                                                   on orthogonal frequency division multi-        More          generally,
                                                   plexing (OFDM), they are considered            Blasco says the HPA
                                                   incompatible and both groups are now           is making a strategic
                                                   lobbying feverishly to have their versions     mistake with its approach
                                                   ratified as the global standard.               and will pay for it later.
                                                       The stakes are high: OPERA partners            He stressed the notch
                                                   recently suggested broadband PLC could         filters implemented in the latest DS2
                                                   achieve 10% market penetration, once a         silicon not only meet the FCC’s exclusion
                                                   standard has been ratified for equipment       bands for BPL in the US, but can be
                                                   and transmission systems.                      adapted, with a simple firmware upgrade,
                                                       Luis Legorburu, the group’s project        to meet all countries’ regulatory require-
                                                   coordinator, said agreement would boost        ments for hf radio.
                                                   utilities’ commitment to use PLC, espe-            And he adds that, since the OPERA
                                                   cially if they could link broadband access     specification and DS2’s 200Mbit/s sili-
                                                   provision to other services, such as auto-     con have been tested in numerous field
                                                   matic meter reading and electricity net-       trials in the US and Europe: “It is well
                                                   work control.                                  ahead of any other proposal for broad-
                                                       “We will defend [our specification]        band over powerline.”
                                                   over the remainder of the project and              Whatever the rights or wrongs, both
                                                   hope it will lead to a European PLC stan-      groups agree they need to focus on real
                                                   dard,” said Legorburu.                         deployments and to show that BLP/PLC
                                                       Because of the huge potential, a war       can compete with established access
                                                   of words has broken out after some US          technologies.




N e w E l e c t r o n i c s w w w. n e o n . c o . u k 9 M a y 2 0 0 6                                                                           19

								
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